Sorghum has the potential to perform better in CQ

DAF senior regional research agronomist, Darren Aisthorpe, Emerald, said there was no doubt sorghum had the potential to perform better in CQ. 

“Planter technology has evolved significantly and we’re now at a point where we’ve adopted precision placement, we’ve got the ability to put seeds where we want them, how we want them, when we want them and that can have huge ramifications for agronomy going forward,” he said.

“We’ve got a broad range of new hybrid genetics coming through which offer yield boosts over Buster and other key varieties of the time, so there’s options there to really push our yield potential if we want to go for it. 

“Around P and K deep placement, our nutritional percentage has improved significantly, and we’re starting to collect the dividends as a result of that work, but unfortunately our yield potential conversion is still not ideal. 

“What we need to do is somehow find a balance between number of plants, number of tillers, and screenings, and maximising yields.” 

Pacific Seeds summer grains agronomist Trevor Philp said there was still large improvements to be made, a positive thing for both growers and the industry.

“We’ve had the same type of hybrid in the market for nearly 30 years, so it’s time maybe to look at different things, and that can be a scary thing for a breeding company to make a big change in their breeding program and go away from what works already,” he said. 

“Central Queensland is a big market for us, and I think it’s come to a time where we need varieties specifically adapted to certain areas.

“If we want to get the productivity gain, we’re going to have to be a bit more flexible.

“We can’t have hybrids that work in Emerald and Gunnedah, and I think the system is going to be a little different as well. As we change hybrids we’ll have to change the agronomy to suit.” 

Research suggests sorghum growers can achieve significant yield increases by better matching hybrid selection and agronomic management to local growing conditions and seasonal outlooks.

With higher yielding hybrids offering new attributes and characteristics now available, it’s important that appropriate agronomic management is implemented if growers are to reap the productivity benefits.

Extensive research into sorghum agronomy in central Queensland during the late 1990s and early 2000s by the CQ sustainable farming systems project helped bridge knowledge gaps on the effect of row configuration and plant population in low, intermediate and high yielding environments.

However, agronomic practices, technology and sorghum genetics have since evolved to a point where gaps again exist around how to optimise yield and quality for some of the new high yielding hybrids on the market. 

In 2014, the Queensland Alliance for Agriculture and Food Innovation (QAAFI) led a GRDC funded trial program focusing on a range of agronomic configurations including population x hybrid in various environments and row spacing configurations, with the aim of maximising yield with newer hybrid types and determining whether existing agronomy rules of thumb require updating.

Mr Aisthorpe said this trial data highlighted the need for more research into optimising individual hybrid yield for a given amount of plant available water (PAW).

“Trial results showed considerable yield variations for any one amount of PAW, suggesting that growers who optimise planting configurations to suit a given hybrid and the conditions it is being planted into, can derive significant benefits,” he said.

“While maximising yield for the water available to the plant is generally always the goal of growers, achieving this at the cost of high screenings and possibly severe dockage or screening costs to make the product marketable is not.”

Trial work in 2017 in central Queensland, as part of the QAAFI/GRDC project planted four hybrids on both skip row and solid one metre row spacing configurations, at three different population densities.

Non-limiting supplies of nitrogen and phosphorus and a full profile of moisture at planting were provided, with the trial then subsequently treated as a dryland crop.

Mr Aisthorpe said yield responses clearly showed that the solid one metre row spacing, high population configuration, maximised yields for the trial conditions for all hybrids.

“How each hybrid developed yield was also assessed, with all four hybrids showing that as population increases, tiller contribution to total yield declines – a result that’s been consistent across a range of research work,” he said.

“However, when grain size is considered, we observed average screenings for two of the hybrids starting to spike above five per cent, and individual plot results in excess of 10 per cent for some of the solid row spacing, higher population treatments.

“This raises some interesting questions over which agronomic management strategies are best suited to the newer varieties.”